Method and apparatus for drawing glass cylinders



Mwzss June 26, 1923.

T. STENHOUSE METHOD AND APPARATUS FOR DRAWING GLASS CYLINDERS Filed Nov. 25, 1919 wvmvron ffiwJ z/zlm BY ATTORNEY Patented June 2%, W23.

THOMAfi STENHOUSE, OF WASHINGTON, PENNSYLVANIA, ASSIGNOR, BY DIRECT AND' rate,

ears

MESNE ASSIGNMENTS, OF ONE-SIXTH TO ALEXANDER I1. DUVAL DADRIAN, OE WASHINGTON, PENNSYLVANIA, AND ONE-SIXTH TO BEBNHABD F. DBAJKENFELD,

JR, 015 NEW YORK, N. Y.

METHOD AND APPARATUS FOR DRAWING GLASS CYLINDER/S.

Application filed November 25, 1919. Serial No. 340,829.

To all whom it may concern;-

Be it known that I, THOMAS STENHOUSE, a citizen of the United States, and resident of the town and county of Washington, State of Pennsylvania, have invented new and useful Improvements in Methods and Apparatus for Drawing Glass Cylinders, of which the following is a specification.

This invention relates to an improved method and apparatus for drawing glass cylinders, and has for its primary object and purpose to provide improved means where by the speed of the draw may be accurately regulated and controlled in a uniform manner for the drawing of cylinders of pre-determined diameter and thickness and in proportion to the rate of cooling of the molten glass.

In the art relating to the manufacture of window glass, the glass is first drawn from a molten bath contained in a pot by means of a bait, a suitable lifting or holstmg apparatus being employed for raising the bait. When the fact is borne in mind that the molten glass contained in the pot is cooling at a rate which is proportionate to the lower 4 ing of the body of glass in the pot, and the simultaneously raising or drawing of the cylinder, it is manifest that a correspond ng proportionate, evenly accelerated drawing speed is necessary in order to meet these conditions, whereby an accurately drawn cylinder of predetermined diameter an thickness will be formed. In the practice of the art, it has been demonstrated that time and speed may be relatively employed to formulate a well-defined curve, and the essential concept of the present nvention resides in the evolution of a composite curve, and therefrom producing a part conforming to said curve whereby the operation of the hoisting apparatus may be automatically controlled. In this manner, when the temperature of the glass has been ascertained, a proportionate and evenly accelerated rate of speed during the draw is maintained, thus bility, the cylinder is frequently unevenly Due to lack ofskill, inadvertence or other human falli-,

drawn. As a complete insurance against such defective cylinders, and to provide means for the definite automatic control of the hoisting or drawing apparatus, my present invention has been designed.

More particularly considered, the present improvement comprehends the provision of a rheostat for controlling the operation of the hoisting apparatus, a rotatably mounted cam element, a variable speed motor geared to the cam element and means cooperating with the cam element and actuated thereby to automatically operate the movable switch of the rheostat.

With the above and other objects in view, the present invention contemplates the provision of an improved method and a paratus for drawing glass cylinders as a ove characterized, and the form, construction and relative arrangement of the several parts of such apparatus as will be hereinafter more fully described, illustrated in the accompanying drawings and subsequently incorporated in the subjoined claims.

In the drawin wherein I have illustrated one practical em odiment of my invention, and in which similar reference characters designate corresponding parts throughout the several views, Fig. 1 is a front side elevation, and Fig. 2 is a top plan view.

For purposes of illustration I have disclosed an apparatus in, the accompanying 1 drawing consisting of a rheostat 1, which is electrically connected to a motor (not shown), which in turn operates a bait hoisting apparatus of the usual form. To the spindle or shaft 2 of the control lever 3 of the rheostat a spur gear i is keyed or otherwise fixed. This gear meshes with a rack 5. A roller 6 is mounted upon one endof the rack bar and has peripheral contact with a cam 7 which is fixed upon a shaft 8. On this cam shaft, a worm gear 9 is keyed and is driven by the worm 10 on the shaft 11. A worm wheel 12 on said shaft is engaged by a worm on the motor shaft 13. The speed of the motor 14 is controlled and regulated by means of a rheostat 15 having the usual switch lever 16.

The peripheral outline for the cam 7 is determined by first placing a card or disk, shown at D in dotted lines, in the place to be occupied by the cam and engaging the point of a pencil or other marker with the surface of this disk in the position corresponding to the contact roller 6 in readiness for the start of the drawing operation. The rheostat lever 16 is then moved to a position to set the motor 14: in operation, the speed of operation of this motor being predeterminedin accordance with the known temperatureof the molten body of glass from which the cylinder is to be drawn. At the same time the operator-moves the lever 3 of the rheostat 1, so that the hoisting apparatus will be operated at a suitable speed to form a cylinder of the required diameter and thickness. In this operation of the rheostat lever 3, the rack 5 is shifted and a curved line will be drawn by the encil or marker on the surface of the disk This line is indicative of the decrease in temperature or cooling of the molten glass bath during the drawing operation. This preliminary drawing operation is repeated a number of times so that a number of cards are thus marked with the cooling curve. From these cards a composite curve is made which is indicative of the mean rate of cooling of the molten glass in the bath. The cam element 7 is now constructed with its peripheral outline corresponding to the mean cooling curve which has been first ascertained in the manner above stated. It is now only necessary to fix this cam element 7 on the shaft 8 in contact with the roller 6 on the end of the rack 5. In the subsequent drawing operations, the drawing of the cylinder will proceed at the proper rate of speed and at a speed acceleration which is proportionate to the decreasing temperature of the bath. Thus, when the molten glass has been delivered to the pot by the ordinary means provided for this purpose and the bait has been lowered into the molten glass and left in contact therewith for a suflicient time to cause the glass to adhere to the bait, the operator moves the lever 16 into operative contact with the rheostat 15, which sets the motor 14: in operation. Through the medium of the Worm gearing, motion is thus imparted to the cam 7 and as this cam is in contact with the roller 6, the rack 5 is given a rectilinear movement, and through the medium of the gear 4, the lever 3 is moved into engagement with the resistance contacts 17 on the rheo- I erated proportionately throughout the glass. Accordingly, when the temperature of the glass is ascertained, it is only necessary to position the lever 16 at a suitable point on the rheostat 15, so that the motor 14 will be driven at the necessary speed to insure the desired proportionate acceleration in the speed of draw through the medium of the cam 7.

By first ascertainin the mean cooling curve of the glass in t e manner above described, this cam 7 may be made in a plurality of forms in accordance with the desired diameter and thickness of the cylinder to be drawn.

From the foregoing description considered in connection with the accompanying drawing, my improved method of drawing glass cylinders and the means whereby this method may be successfully practiced will be clearly and fully understood. It will be appreciated that the invention in operation will be accurate and reliable, and as the mechanism which I have devised for governing or controlling the speed of draw for the cylinder, is exceedingly simple, it will be apparent that the invention can be produced at comparatively small manufacturing cost. I have herein shown and described one embodiment of my invention which I believe to be. satisfactory in practical use,

but it will be understood that the device may also be exemplified in numerous other alternative modifications, and I therefore do not desire to be restricted to the specific example above referred to, but reserve the privi lege of resorting to such legitimate changes in the form, construction and arrangement of the several parts as may be fairly embodied within the spirit and scope ofthe invention as claimed.

I claim:

1. The method of producin predetermined form and thic ess, which consists in drawing the article from. a bath of molten plastic material and proportioning the speed of acceleration of the drawing operation according to the mean rate of cooling of the molten plastic material in the bath.

2. In mechanism to control the speed of acceleration of drawing glass cylinders, a movablepart controlling the operation of the drawing apparatus and mechanism to automatically actuate said movable part at a predetermined rate of speed to operate the drawing apparatus and uniformly increase the speed of draw at a rate predetermined by the temperature of the material and the diameter and thickness of the c linder.

3. In mechanism to control t e speed of acceleration of drawing glass cylinders, a movable art controlling the operation of the drawin apparatus, and mechanism to automatical y actuate said movable part, including arectilinearly movable element, a

articles of menses cam coacting with said element, and means to operate said cam at a predetermined speed whereby the speed of the drawing operation is automatically increased in proportion to the decrease in temperature of the glass.

1. In mechanism to control the speed of acceleration of drawing glass cylinders. drawing apparatus including a movable part and mechanism to automatically actuate said movable part comprising an element operatively connected with the movable part ot the drawing appa 'atus, a cam co-acting with said element and of a form determined by the diameter and thickness or" the cylinder to he drawn, and means for rotating the cam at a speed predetermined in respect to the temperatureot the glass.

In mechanism to control the speed of acceleration of drawing glass cylinders, a movable part controlling the speed of operation of a drawing apparatus, and mechanism to automatically actuate said movable part including: a motor driven cam having a fixed peripheral outline predetermined with respect to the temperature of the glass to thel'elrv etl'ect a proportionately accelerated. speed of operation of the drawing apparatus.

(3. in the art of glass manufacture. mechanism to control the speed of acccleration of operation of a glass cylinder draw in; apparatus including a cam having a fixed predetermined curvilinear outline coni'orinino' to the cooling curve of the glass durin; the drawing oiiieration. and designed to eii'ect an accelerated increase in the speed of the draw in accordance with the desired diameter and thickness of the tylilltltfl.

in testimony that 1 claim the foregoing as my invention. 1 have signed my name hereunder.

TillUlilAS STENHUUSE. 

